天窓

1. Origins, structure, and basic meaning

• Structure: 天窓 (てんまど) is a window set in a roof or ceiling. 天窓から marks the path of incoming light; 天窓を開ける makes it an operated object.
• Basic usage: Morning light enters through a skylight, and an attic skylight is opened for ventilation.

2. Common pitfalls and similar expressions

• Opening admitting light and window opened for air
  • から identifies a passage for light; を marks the fixture being operated. Its roof or ceiling position distinguishes it from an ordinary wall 窓.